XML is the emerging standard
for representing knowledge in almost arbitrary applications. At least
almost every kind of knowledge can be represented in XML. For
exploring such knowledge, one needs a search engine which is able to
let users benefit from all of the concepts with which XML blesses the
world.

HyREX is the Hyper-media
Retrieval Engine for XML
[Abolhassani/etal:02]
. The
HyREX project is an ongoing effort (funded as part of other
projects like e. g. CARMEN, CYCLADES, and CLASSIX) for developing an
information retrieval engine for XML documents. HyREX's main
characteristics can be derived from the constituents of its
name:

hyper

HyREX offers explicit and implicit links to the user.
Explicit links are specified within the documents, usually by means
of XML linking standards, such as XLink and XPointer. Implicit links
are intrinsic to information structures which \hyrex derives from
XML document collections.

media

HyREX offers search facilities for text, but also for other
media than text, at least conceptually.

retrieval engine

HyREX allows users to explore all kinds of information
structures available through XML; besides retrieval in XML
documents it allows for browsing and searching the domains
of attributes of XML documents as well as schema information
given for example by the DTD of a document collection.

XML

HyREX allows retrieval under consideration of content
and structure inherent in XML documents.

Architecture

HyREX's architecture is similar to that of database management
systems. Thus, there is a clear separation between the logical
and the physical level. The physical layer HyPath
deals with efficient access paths for retrieval, while the
logical layer deals with the XIRQL
query language. On top of these layers is HyGate, the
user interface to HyREX applications.

In the following we give a brief outline on the
characteristics of the levels.

HyGate

User interface for searching and browsing

Query formulation assistant

Presentation of retrieval results

XIRQL

XML Information Retrieval Query Language

extends XPath with IR capabilities

Weighted document content and query conditions

Ranking for search results

Powerful searching for any type of information

Relevance-oriented search

HyPath

Efficient access paths for content and structure

application specific selection of access paths

Publikationen

Mohammad Abolhassani; Norbert Fuhr; Saadia Malik (2004).

HyREX at INEX 2003. In INitiative for the Evaluation of XML Retrieval (INEX). Proceedings of the Second INEX Workshop. Dagstuhl, Germany, December 15--17, 2003